Phenolic resins have utility in both the uncarbonized and carbonized forms, the choice of forms being dependent upon the performance criteria required for specific applications. In the uncarbonized form, phenolic resins can be used, for example, as adhesives, coatings, and matrix resins. Although phenolic resins are typically thermally stable and resistant to chemical attack, most unfilled and/or unmodified phenolic resins have a maximum use temperature of &lt;200.degree. C. The utility of phenolic resins in the uncarbonized form would be extended and enhanced if the thermal stability of the resins were improved. In the carbonized form, phenolic resins are useful, for example, as prepreg and densification resins. As a prepreg resin, the phenolic resin, in the uncarbonized form, serves to bind together or laminate various articles.
Japanese patent application No. 81,454, filed Apr. 23, 1984, relates to the production of beta type SiC by heating a silicon and carbon containing raw material in a non-oxidizing atmosphere using catalysts such as mineral acids.
The present invention describes inherently oxidation resistant, high char resins. The resins of this invention are based on ceramic precursor polymers, i.e., metal-organic polymers which yield ceramic/refractory phases upon pyrolysis. This patent application describes silazane-modified phenolic resins and their utility in resin matrix composites and adhesives.